1. Field of the Invention
This invention generally relates to the fabrication of micro lens elements. More specifically, the invention relates to apparatus and methods for fabrication of micro lens elements and metal features, such as guide pins or electrical connectors, in a single molding process. The invention allows the optical micro lens and metallic connector elements to be manufactured on a common substrate for the first time.
2. Background Art
For parallel optic applications, lens components are used to facilitate coupling light into a detector array. In order to achieve low cost, molded plastic optics has been used for fiber-to-detector coupling. Two basic types, thermoplastic and thermoset materials, have been employed in industry-standard multi-fiber push-on (MPO) connectors and in the multi-fiber termination (MT) ferrules which form the basis of these connector systems.
The industry standard for parallel optical interconnects is based on the MPO connector, as standardized by the Telecommunications Industry of America (TIA). This connector achieves optical alignment by using a pair of high precision metal guide pins to interface with a corresponding set of precision holes fabricated in the optical receptacle, as shown in FIGS. 1, 2 and 3. In particular, FIG. 1 illustrates an example of a conventional photodetector array 12 with an MPO optical fiber array interface 14 using precision metal guide pins 16. FIG. 2 shows an example of a conventional lens array 22 and guide pin assembly 24 for photodetector arrays with an MPO optical interface 26 (both schematic and side views), and FIG. 3 illustrates a conventional manually positioned micro lens array 32 within an MPO optical connector 34.
Current designs fabricate the MPO connector interface and coupling lenses as separate processes and manually assemble them into a finished product; this requires active alignment (often an expensive, manual process) and cannot fully take advantage of the precision alignment designed into the MPO interface.